From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v5 net-next] net: phy: Add Edge-rate driver for Microsemi PHYs. Date: Tue, 04 Oct 2016 00:48:59 -0400 (EDT) Message-ID: <20161004.004859.1105270097322633239.davem@davemloft.net> References: <1475479393-24308-1-git-send-email-Raju.Lakkaraju@microsemi.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Allan.Nielsen-dzo6w/eZyo2tG0bUXCXiUA@public.gmane.org, andrew-g2DYL2Zd6BY@public.gmane.org To: Raju.Lakkaraju-dzo6w/eZyo2tG0bUXCXiUA@public.gmane.org Return-path: In-Reply-To: <1475479393-24308-1-git-send-email-Raju.Lakkaraju-dzo6w/eZyo2tG0bUXCXiUA@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org From: Raju Lakkaraju Date: Mon, 3 Oct 2016 12:53:13 +0530 > From: Raju Lakkaraju > > Edge-rate: > As system and networking speeds increase, a signal's output transition, > also know as the edge rate or slew rate (V/ns), takes on greater importance > because high-speed signals come with a price. That price is an assortment of > interference problems like ringing on the line, signal overshoot and > undershoot, extended signal settling times, crosstalk noise, transmission > line reflections, false signal detection by the receiving device and > electromagnetic interference (EMI) -- all of which can negate the potential > gains designers are seeking when they try to increase system speeds through > the use of higher performance logic devices. The fact is, faster signaling > edge rates can cause a higher level of electrical noise or other type of > interference that can actually lead to slower line speeds and lower maximum > system frequencies. This parameter allow the board designers to change the > driving strange, and thereby change the EMI behavioral. > > Edge-rate parameters (vddmac, edge-slowdown) get from Device Tree. > > Tested on Beaglebone Black with VSC 8531 PHY. > > Signed-off-by: Raju Lakkaraju Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html